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• MonoTouch and CoreBluetooth Low Energy Required?

  - by user856232

  We are making MFi hardware and an iOS app. We will want to have the BT device notify our app even if we are not running periodically when certain events happen. I know the CoreBluetooth API is the one to use, but can't tell for sure if that API only works with BT Low Energy devices or if it will also work with regular (MFi of course) BT 2.1 and higher devices. So my question is: Does the CoreBluetooth API only work with Bluetooth Low Energy devices or will it also work with 2.1 devices?

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• Low Voting {API(Five Star)} Feedback

  - by D.J.

  Is there any module in drupal which provides low rating feedback. eg If someone wants to vote a content as <= 2 (out of 5). Before he does so, there will be a pop up window displaying text "Are you sure you want to rate so low?" etc. If there is no such module then is there any easy way of doing it?

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• Run a pc on battery for 3 days?

  - by Zen 8000k

  I am looking for a low power, low end pc able to run 24/7 without overheating and a way to support it in case of power failure. Power failures can be up to 72 hours. The pc dosen't need a monitor or keyboard. A modem must also be protected in case of power failure. When i say low end, i don't mean crap. The cpu needs to be x86 and have at least 1k cpu in this chart: http://www.cpubenchmark.net/index.php What's the best way to do this?

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• Determine if the current thread has low I/O priority

  - by Magnus Hoff

  I have a background thread that does some I/O-intensive background type work. To please the other threads and processes running, I set the thread priority to "background mode" using SetThreadPriority, like this: SetThreadPriority(GetCurrentThread(), THREAD_MODE_BACKGROUND_BEGIN); However, THREAD_MODE_BACKGROUND_BEGIN is only available in Windows Server 2008 or newer, as well as Windows Vista and newer, but the program needs to work well on Windows Server 2003 and XP as well. So the real code is more like this: if (!SetThreadPriority(GetCurrentThread(), THREAD_MODE_BACKGROUND_BEGIN)) { SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_LOWEST); } The problem with this is that on Windows XP it will totally disrupt the system by using too much I/O. I have a plan for a ugly and shameful way of mitigating this problem, but that depends on me being able to determine if the current thread has low I/O priority or not. Now, I know I can store which thread priority I ended up setting, but the control flow in the program is not really well suited for this. I would rather like to be able to test later whether or not the current thread has low I/O priority -- if it is in "background mode". GetThreadPriority does not seem to give me this information. Is there any way to determine if the current thread has low I/O priority?

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• unexplainable packet drops with 5 ethernet NICs and low traffic on Ubuntu

  - by jon

  I'm stuck on problem where my machine started to drops packets with no sign of ANY system load or high interrupt usage after an upgrade to Ubuntu 12.04. My server is a network monitoring sensor, running Ubuntu LTS 12.04, it passively collects packets from 5 interfaces doing network intrusion type stuff. Before the upgrade I managed to collect 200+GB of packets a day while writing them to disk with around 0% packet loss depending on the day with the help of CPU affinity and NIC IRQ to CPU bindings. Now I lose a great deal of packets with none of my applications running and at very low PPS rate which a modern workstation NIC would have no trouble with. Specs: x64 Xeon 4 cores 3.2 Ghz 16 GB RAM NICs: 5 Intel Pro NICs using the e1000 driver (NAPI). [1] eth0 and eth1 are integrated NICs (in the motherboard) There are 2 other PCI-X network cards, each with 2 Ethernet ports. 3 of the interfaces are running at Gigabit Ethernet, the others are not because they're attached to hubs. Specs: [2] http://support.dell.com/support/edocs/systems/pe2850/en/ug/t1390aa.htm uptime 17:36:00 up 1:43, 2 users, load average: 0.00, 0.01, 0.05 # uname -a Linux nms 3.2.0-29-generic #46-Ubuntu SMP Fri Jul 27 17:03:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux I also have the CPU governor set to performance mode and irqbalance off. The problem still occurs with them on. # lspci -t -vv -[0000:00]-+-00.0 Intel Corporation E7520 Memory Controller Hub +-02.0-[01-03]--+-00.0-[02]----0e.0 Dell PowerEdge Expandable RAID controller 4 | \-00.2-[03]-- +-04.0-[04]-- +-05.0-[05-07]--+-00.0-[06]----07.0 Intel Corporation 82541GI Gigabit Ethernet Controller | \-00.2-[07]----08.0 Intel Corporation 82541GI Gigabit Ethernet Controller +-06.0-[08-0a]--+-00.0-[09]--+-04.0 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) | | \-04.1 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) | \-00.2-[0a]--+-02.0 Digium, Inc. Wildcard TE210P/TE212P dual-span T1/E1/J1 card 3.3V | +-03.0 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) | \-03.1 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) +-1d.0 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #1 +-1d.1 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #2 +-1d.2 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #3 +-1d.7 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller +-1e.0-[0b]----0d.0 Advanced Micro Devices [AMD] nee ATI RV100 QY [Radeon 7000/VE] +-1f.0 Intel Corporation 82801EB/ER (ICH5/ICH5R) LPC Interface Bridge \-1f.1 Intel Corporation 82801EB/ER (ICH5/ICH5R) IDE Controller I believe the NIC nor the NIC drivers are dropping the packets because ethtool reports 0 under rx_missed_errors and rx_no_buffer_count for each interface. On the old system, if it couldn't keep up this is where the drops would be. I drop packets on multiple interfaces just about every second, usually in small increments of 2-4. I tried all these sysctl values, I'm currently using the uncommented ones. # cat /etc/sysctl.conf # high net.core.netdev_max_backlog = 3000000 net.core.rmem_max = 16000000 net.core.rmem_default = 8000000 # defaults #net.core.netdev_max_backlog = 1000 #net.core.rmem_max = 131071 #net.core.rmem_default = 163480 # moderate #net.core.netdev_max_backlog = 10000 #net.core.rmem_max = 33554432 #net.core.rmem_default = 33554432 Here's an example of an interface stats report with ethtool. They are all the same, nothing is out of the ordinary ( I think ), so I'm only going to show one: ethtool -S eth2 NIC statistics: rx_packets: 7498 tx_packets: 0 rx_bytes: 2722585 tx_bytes: 0 rx_broadcast: 327 tx_broadcast: 0 rx_multicast: 1504 tx_multicast: 0 rx_errors: 0 tx_errors: 0 tx_dropped: 0 multicast: 1504 collisions: 0 rx_length_errors: 0 rx_over_errors: 0 rx_crc_errors: 0 rx_frame_errors: 0 rx_no_buffer_count: 0 rx_missed_errors: 0 tx_aborted_errors: 0 tx_carrier_errors: 0 tx_fifo_errors: 0 tx_heartbeat_errors: 0 tx_window_errors: 0 tx_abort_late_coll: 0 tx_deferred_ok: 0 tx_single_coll_ok: 0 tx_multi_coll_ok: 0 tx_timeout_count: 0 tx_restart_queue: 0 rx_long_length_errors: 0 rx_short_length_errors: 0 rx_align_errors: 0 tx_tcp_seg_good: 0 tx_tcp_seg_failed: 0 rx_flow_control_xon: 0 rx_flow_control_xoff: 0 tx_flow_control_xon: 0 tx_flow_control_xoff: 0 rx_long_byte_count: 2722585 rx_csum_offload_good: 0 rx_csum_offload_errors: 0 alloc_rx_buff_failed: 0 tx_smbus: 0 rx_smbus: 0 dropped_smbus: 01 # ifconfig eth0 Link encap:Ethernet HWaddr 00:11:43:e0:e2:8c UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:373348 errors:16 dropped:95 overruns:0 frame:16 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:356830572 (356.8 MB) TX bytes:0 (0.0 B) eth1 Link encap:Ethernet HWaddr 00:11:43:e0:e2:8d UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:13616 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:8690528 (8.6 MB) TX bytes:0 (0.0 B) eth2 Link encap:Ethernet HWaddr 00:04:23:e1:77:6a UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:7750 errors:0 dropped:471 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2780935 (2.7 MB) TX bytes:0 (0.0 B) eth3 Link encap:Ethernet HWaddr 00:04:23:e1:77:6b UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:5112 errors:0 dropped:206 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:639472 (639.4 KB) TX bytes:0 (0.0 B) eth4 Link encap:Ethernet HWaddr 00:04:23:b6:35:6c UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:961467 errors:0 dropped:935 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:958561305 (958.5 MB) TX bytes:0 (0.0 B) eth5 Link encap:Ethernet HWaddr 00:04:23:b6:35:6d inet addr:192.168.1.6 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:4264 errors:0 dropped:16 overruns:0 frame:0 TX packets:699 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:572228 (572.2 KB) TX bytes:124456 (124.4 KB) I tried the defaults, then started to play around with settings. I wasn't using any flow control and I increased the RxDescriptor count to 4096 before the upgrade as well without any problems. # cat /etc/modprobe.d/e1000.conf options e1000 XsumRX=0,0,0,0,0 RxDescriptors=4096,4096,4096,4096,4096 FlowControl=0,0,0,0,0 debug=16 Here's my network configuration file, I turned off checksumming and various offloading mechanisms along with setting CPU affinity with heavy use interfaces getting an entire CPU and light use interfaces sharing a CPU. I used these settings prior to the upgrade without problems. # cat /etc/network/interfaces # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet manual pre-up /sbin/ethtool -G eth0 rx 4096 tx 0 pre-up /sbin/ethtool -K eth0 gro off gso off rx off pre-up /sbin/ethtool -A eth0 rx off autoneg off up ifconfig eth0 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "4" > /proc/irq/48/smp_affinity down ifconfig eth0 down post-down /sbin/ethtool -G eth0 rx 256 tx 256 post-down /sbin/ethtool -K eth0 gro on gso on rx on post-down /sbin/ethtool -A eth0 rx on autoneg on auto eth1 iface eth1 inet manual pre-up /sbin/ethtool -G eth1 rx 4096 tx 0 pre-up /sbin/ethtool -K eth1 gro off gso off rx off pre-up /sbin/ethtool -A eth1 rx off autoneg off up ifconfig eth1 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "4" > /proc/irq/49/smp_affinity down ifconfig eth1 down post-down /sbin/ethtool -G eth1 rx 256 tx 256 post-down /sbin/ethtool -K eth1 gro on gso on rx on post-down /sbin/ethtool -A eth1 rx on autoneg on auto eth2 iface eth2 inet manual pre-up /sbin/ethtool -G eth2 rx 4096 tx 0 pre-up /sbin/ethtool -K eth2 gro off gso off rx off pre-up /sbin/ethtool -A eth2 rx off autoneg off up ifconfig eth2 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "1" > /proc/irq/82/smp_affinity down ifconfig eth2 down post-down /sbin/ethtool -G eth2 rx 256 tx 256 post-down /sbin/ethtool -K eth2 gro on gso on rx on post-down /sbin/ethtool -A eth2 rx on autoneg on auto eth3 iface eth3 inet manual pre-up /sbin/ethtool -G eth3 rx 4096 tx 0 pre-up /sbin/ethtool -K eth3 gro off gso off rx off pre-up /sbin/ethtool -A eth3 rx off autoneg off up ifconfig eth3 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "2" > /proc/irq/83/smp_affinity down ifconfig eth3 down post-down /sbin/ethtool -G eth3 rx 256 tx 256 post-down /sbin/ethtool -K eth3 gro on gso on rx on post-down /sbin/ethtool -A eth3 rx on autoneg on auto eth4 iface eth4 inet manual pre-up /sbin/ethtool -G eth4 rx 4096 tx 0 pre-up /sbin/ethtool -K eth4 gro off gso off rx off pre-up /sbin/ethtool -A eth4 rx off autoneg off up ifconfig eth4 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "4" > /proc/irq/77/smp_affinity down ifconfig eth4 down post-down /sbin/ethtool -G eth4 rx 256 tx 256 post-down /sbin/ethtool -K eth4 gro on gso on rx on post-down /sbin/ethtool -A eth4 rx on autoneg on auto eth5 iface eth5 inet static pre-up /etc/fw.conf address 192.168.1.1 netmask 255.255.255.0 broadcast 192.168.1.255 gateway 192.168.1.1 dns-nameservers 192.168.1.2 192.168.1.3 up ifconfig eth5 up post-up echo "8" > /proc/irq/77/smp_affinity down ifconfig eth5 down Here's a few examples of packet drops, i ran one after another, probabling totaling 3 or 4 seconds. You can see increases in the drops from the 1st and 3rd. This was a non-busy time, very little traffic. # awk '{ print $1,$5 }' /proc/net/dev Inter-| face drop eth3: 225 lo: 0 eth2: 505 eth1: 0 eth5: 17 eth0: 105 eth4: 1034 # awk '{ print $1,$5 }' /proc/net/dev Inter-| face drop eth3: 225 lo: 0 eth2: 507 eth1: 0 eth5: 17 eth0: 105 eth4: 1034 # awk '{ print $1,$5 }' /proc/net/dev Inter-| face drop eth3: 227 lo: 0 eth2: 512 eth1: 0 eth5: 17 eth0: 105 eth4: 1039 I tried the pci=noacpi options. With and without, it's the same. This is what my interrupt stats looked like before the upgrade, after, with ACPI on PCI it showed multiple NICs bound to an interrupt and shared with other devices such as USB drives which I didn't like so I think i'm going to keep it with ACPI off as it's easier to designate sole purpose interrupts. Is there any advantage I would have using the default i.e. ACPI w/ PCI. ? # cat /etc/default/grub | grep CMD_LINE GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1 noacpi pci=noacpi" GRUB_CMDLINE_LINUX="" # cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 0: 45 0 0 16 IO-APIC-edge timer 1: 1 0 0 7936 IO-APIC-edge i8042 2: 0 0 0 0 XT-PIC-XT-PIC cascade 6: 0 0 0 3 IO-APIC-edge floppy 8: 0 0 0 1 IO-APIC-edge rtc0 9: 0 0 0 0 IO-APIC-edge acpi 12: 0 0 0 1809 IO-APIC-edge i8042 14: 1 0 0 4498 IO-APIC-edge ata_piix 15: 0 0 0 0 IO-APIC-edge ata_piix 16: 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb2 18: 0 0 0 1350 IO-APIC-fasteoi uhci_hcd:usb4, radeon 19: 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb3 23: 0 0 0 4099 IO-APIC-fasteoi ehci_hcd:usb1 38: 0 0 0 61963 IO-APIC-fasteoi megaraid 48: 0 0 1002319 4 IO-APIC-fasteoi eth0 49: 0 0 38772 3 IO-APIC-fasteoi eth1 77: 0 0 130076 432159 IO-APIC-fasteoi eth4 78: 0 0 0 23917 IO-APIC-fasteoi eth5 82: 1329033 0 0 4 IO-APIC-fasteoi eth2 83: 0 4886525 0 6 IO-APIC-fasteoi eth3 NMI: 5 6 4 5 Non-maskable interrupts LOC: 61409 57076 64257 114764 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts IWI: 0 0 0 0 IRQ work interrupts RES: 17956 25333 13436 14789 Rescheduling interrupts CAL: 22436 607 539 478 Function call interrupts TLB: 1525 1458 4600 4151 TLB shootdowns TRM: 0 0 0 0 Thermal event interrupts THR: 0 0 0 0 Threshold APIC interrupts MCE: 0 0 0 0 Machine check exceptions MCP: 16 16 16 16 Machine check polls ERR: 0 MIS: 0 Here's sample output of vmstat, showing the system. Barebones system right now. root@nms:~# vmstat -S m 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 0 14992 192 1029 0 0 56 2 419 29 1 0 99 0 0 0 0 14992 192 1029 0 0 0 0 922 27 0 0 100 0 0 0 0 14991 192 1029 0 0 0 36 763 50 0 0 100 0 0 0 0 14991 192 1029 0 0 0 0 646 35 0 0 100 0 0 0 0 14991 192 1029 0 0 0 0 722 54 0 0 100 0 0 0 0 14991 192 1029 0 0 0 0 793 27 0 0 100 0 ^C Here's dmesg output. I can't figure out why my PCI-X slots are negotiated as PCI. The network cards are all PCI-X with the exception of the integrated NICs that came with the server. In the output below it looks as if eth3 and eth2 negotiated at PCI-X speeds rather than PCI:66Mhz. Wouldn't they all drop to PCI:66Mhz? If your integrated NICs are PCI, as labeled below (eth0,eth1), then wouldn't all devices on your bus speed drop down to that slower bus speed? If not, I still don't know why only one of my NICs ( each has two ethernet ports) is labeled as PCI-X in the output below. Does that mean it is running at PCI-X speeds are is it showing that it's capable? # dmesg | grep e1000 [ 3678.349337] e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI [ 3678.349342] e1000: Copyright (c) 1999-2006 Intel Corporation. [ 3678.349394] e1000 0000:06:07.0: PCI->APIC IRQ transform: INT A -> IRQ 48 [ 3678.409725] e1000 0000:06:07.0: Receive Descriptors set to 4096 [ 3678.409730] e1000 0000:06:07.0: Checksum Offload Disabled [ 3678.409734] e1000 0000:06:07.0: Flow Control Disabled [ 3678.586409] e1000 0000:06:07.0: eth0: (PCI:66MHz:32-bit) 00:11:43:e0:e2:8c [ 3678.586419] e1000 0000:06:07.0: eth0: Intel(R) PRO/1000 Network Connection [ 3678.586642] e1000 0000:07:08.0: PCI->APIC IRQ transform: INT A -> IRQ 49 [ 3678.649854] e1000 0000:07:08.0: Receive Descriptors set to 4096 [ 3678.649859] e1000 0000:07:08.0: Checksum Offload Disabled [ 3678.649863] e1000 0000:07:08.0: Flow Control Disabled [ 3678.826436] e1000 0000:07:08.0: eth1: (PCI:66MHz:32-bit) 00:11:43:e0:e2:8d [ 3678.826444] e1000 0000:07:08.0: eth1: Intel(R) PRO/1000 Network Connection [ 3678.826627] e1000 0000:09:04.0: PCI->APIC IRQ transform: INT A -> IRQ 82 [ 3679.093266] e1000 0000:09:04.0: Receive Descriptors set to 4096 [ 3679.093271] e1000 0000:09:04.0: Checksum Offload Disabled [ 3679.093275] e1000 0000:09:04.0: Flow Control Disabled [ 3679.130239] e1000 0000:09:04.0: eth2: (PCI-X:133MHz:64-bit) 00:04:23:e1:77:6a [ 3679.130246] e1000 0000:09:04.0: eth2: Intel(R) PRO/1000 Network Connection [ 3679.130449] e1000 0000:09:04.1: PCI->APIC IRQ transform: INT B -> IRQ 83 [ 3679.397312] e1000 0000:09:04.1: Receive Descriptors set to 4096 [ 3679.397318] e1000 0000:09:04.1: Checksum Offload Disabled [ 3679.397321] e1000 0000:09:04.1: Flow Control Disabled [ 3679.434350] e1000 0000:09:04.1: eth3: (PCI-X:133MHz:64-bit) 00:04:23:e1:77:6b [ 3679.434360] e1000 0000:09:04.1: eth3: Intel(R) PRO/1000 Network Connection [ 3679.434553] e1000 0000:0a:03.0: PCI->APIC IRQ transform: INT A -> IRQ 77 [ 3679.704072] e1000 0000:0a:03.0: Receive Descriptors set to 4096 [ 3679.704077] e1000 0000:0a:03.0: Checksum Offload Disabled [ 3679.704081] e1000 0000:0a:03.0: Flow Control Disabled [ 3679.738364] e1000 0000:0a:03.0: eth4: (PCI:33MHz:64-bit) 00:04:23:b6:35:6c [ 3679.738371] e1000 0000:0a:03.0: eth4: Intel(R) PRO/1000 Network Connection [ 3679.738538] e1000 0000:0a:03.1: PCI->APIC IRQ transform: INT B -> IRQ 78 [ 3680.046060] e1000 0000:0a:03.1: eth5: (PCI:33MHz:64-bit) 00:04:23:b6:35:6d [ 3680.046067] e1000 0000:0a:03.1: eth5: Intel(R) PRO/1000 Network Connection [ 3682.132415] e1000: eth0 NIC Link is Up 100 Mbps Half Duplex, Flow Control: None [ 3682.224423] e1000: eth1 NIC Link is Up 100 Mbps Half Duplex, Flow Control: None [ 3682.316385] e1000: eth2 NIC Link is Up 100 Mbps Half Duplex, Flow Control: None [ 3682.408391] e1000: eth3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None [ 3682.500396] e1000: eth4 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None [ 3682.708401] e1000: eth5 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX At first I thought it was the NIC drivers but I'm not so sure. I really have no idea where else to look at the moment. Any help is greatly appreciated as I'm struggling with this. If you need more information just ask. Thanks! [1]http://www.cs.fsu.edu/~baker/devices/lxr/http/source/linux/Documentation/networking/e1000.txt?v=2.6.11.8 [2] http://support.dell.com/support/edocs/systems/pe2850/en/ug/t1390aa.htm

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• High Linux loads on low CPU/memory usage

  - by user13323

  Hi. I have quite strange situation, where my CentOS 5.5 box loads are high, but the CPU and memory used are pretty low: top - 20:41:38 up 42 days, 6:14, 2 users, load average: 19.79, 21.25, 18.87 Tasks: 254 total, 1 running, 253 sleeping, 0 stopped, 0 zombie Cpu(s): 3.8%us, 0.3%sy, 0.1%ni, 95.0%id, 0.6%wa, 0.0%hi, 0.1%si, 0.0%st Mem: 4035284k total, 4008084k used, 27200k free, 38748k buffers Swap: 4208928k total, 242576k used, 3966352k free, 1465008k cached free -mt total used free shared buffers cached Mem: 3940 3910 29 0 37 1427 -/+ buffers/cache: 2445 1495 Swap: 4110 236 3873 Total: 8050 4147 3903 Iostat also shows good results: avg-cpu: %user %nice %system %iowait %steal %idle 3.83 0.13 0.41 0.58 0.00 95.05 Here is the ps aux output: USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 1 0.0 0.0 10348 80 ? Ss 2010 2:11 init [3] root 2 0.0 0.0 0 0 ? S< 2010 0:00 [migration/0] root 3 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/0] root 4 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/0] root 5 0.0 0.0 0 0 ? S< 2010 0:02 [migration/1] root 6 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/1] root 7 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/1] root 8 0.0 0.0 0 0 ? S< 2010 0:02 [migration/2] root 9 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/2] root 10 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/2] root 11 0.0 0.0 0 0 ? S< 2010 0:02 [migration/3] root 12 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/3] root 13 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/3] root 14 0.0 0.0 0 0 ? S< 2010 0:03 [migration/4] root 15 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/4] root 16 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/4] root 17 0.0 0.0 0 0 ? S< 2010 0:01 [migration/5] root 18 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/5] root 19 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/5] root 20 0.0 0.0 0 0 ? S< 2010 0:11 [migration/6] root 21 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/6] root 22 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/6] root 23 0.0 0.0 0 0 ? S< 2010 0:01 [migration/7] root 24 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/7] root 25 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/7] root 26 0.0 0.0 0 0 ? S< 2010 0:00 [migration/8] root 27 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/8] root 28 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/8] root 29 0.0 0.0 0 0 ? S< 2010 0:00 [migration/9] root 30 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/9] root 31 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/9] root 32 0.0 0.0 0 0 ? S< 2010 0:08 [migration/10] root 33 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/10] root 34 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/10] root 35 0.0 0.0 0 0 ? S< 2010 0:05 [migration/11] root 36 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/11] root 37 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/11] root 38 0.0 0.0 0 0 ? S< 2010 0:02 [migration/12] root 39 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/12] root 40 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/12] root 41 0.0 0.0 0 0 ? S< 2010 0:14 [migration/13] root 42 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/13] root 43 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/13] root 44 0.0 0.0 0 0 ? S< 2010 0:04 [migration/14] root 45 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/14] root 46 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/14] root 47 0.0 0.0 0 0 ? S< 2010 0:01 [migration/15] root 48 0.0 0.0 0 0 ? SN 2010 0:00 [ksoftirqd/15] root 49 0.0 0.0 0 0 ? S< 2010 0:00 [watchdog/15] root 50 0.0 0.0 0 0 ? S< 2010 0:00 [events/0] root 51 0.0 0.0 0 0 ? S< 2010 0:00 [events/1] root 52 0.0 0.0 0 0 ? S< 2010 0:00 [events/2] root 53 0.0 0.0 0 0 ? S< 2010 0:00 [events/3] root 54 0.0 0.0 0 0 ? S< 2010 0:00 [events/4] root 55 0.0 0.0 0 0 ? S< 2010 0:00 [events/5] root 56 0.0 0.0 0 0 ? S< 2010 0:00 [events/6] root 57 0.0 0.0 0 0 ? S< 2010 0:00 [events/7] root 58 0.0 0.0 0 0 ? S< 2010 0:00 [events/8] root 59 0.0 0.0 0 0 ? S< 2010 0:00 [events/9] root 60 0.0 0.0 0 0 ? S< 2010 0:00 [events/10] root 61 0.0 0.0 0 0 ? S< 2010 0:00 [events/11] root 62 0.0 0.0 0 0 ? S< 2010 0:00 [events/12] root 63 0.0 0.0 0 0 ? S< 2010 0:00 [events/13] root 64 0.0 0.0 0 0 ? S< 2010 0:00 [events/14] root 65 0.0 0.0 0 0 ? S< 2010 0:00 [events/15] root 66 0.0 0.0 0 0 ? S< 2010 0:00 [khelper] root 107 0.0 0.0 0 0 ? S< 2010 0:00 [kthread] root 126 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/0] root 127 0.0 0.0 0 0 ? S< 2010 0:03 [kblockd/1] root 128 0.0 0.0 0 0 ? S< 2010 0:01 [kblockd/2] root 129 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/3] root 130 0.0 0.0 0 0 ? S< 2010 0:05 [kblockd/4] root 131 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/5] root 132 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/6] root 133 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/7] root 134 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/8] root 135 0.0 0.0 0 0 ? S< 2010 0:02 [kblockd/9] root 136 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/10] root 137 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/11] root 138 0.0 0.0 0 0 ? S< 2010 0:04 [kblockd/12] root 139 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/13] root 140 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/14] root 141 0.0 0.0 0 0 ? S< 2010 0:00 [kblockd/15] root 142 0.0 0.0 0 0 ? S< 2010 0:00 [kacpid] root 281 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/0] root 282 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/1] root 283 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/2] root 284 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/3] root 285 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/4] root 286 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/5] root 287 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/6] root 288 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/7] root 289 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/8] root 290 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/9] root 291 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/10] root 292 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/11] root 293 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/12] root 294 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/13] root 295 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/14] root 296 0.0 0.0 0 0 ? S< 2010 0:00 [cqueue/15] root 299 0.0 0.0 0 0 ? S< 2010 0:00 [khubd] root 301 0.0 0.0 0 0 ? S< 2010 0:00 [kseriod] root 490 0.0 0.0 0 0 ? S 2010 0:00 [khungtaskd] root 493 0.1 0.0 0 0 ? S< 2010 94:48 [kswapd1] root 494 0.0 0.0 0 0 ? S< 2010 0:00 [aio/0] root 495 0.0 0.0 0 0 ? S< 2010 0:00 [aio/1] root 496 0.0 0.0 0 0 ? S< 2010 0:00 [aio/2] root 497 0.0 0.0 0 0 ? S< 2010 0:00 [aio/3] root 498 0.0 0.0 0 0 ? S< 2010 0:00 [aio/4] root 499 0.0 0.0 0 0 ? S< 2010 0:00 [aio/5] root 500 0.0 0.0 0 0 ? S< 2010 0:00 [aio/6] root 501 0.0 0.0 0 0 ? S< 2010 0:00 [aio/7] root 502 0.0 0.0 0 0 ? S< 2010 0:00 [aio/8] root 503 0.0 0.0 0 0 ? S< 2010 0:00 [aio/9] root 504 0.0 0.0 0 0 ? S< 2010 0:00 [aio/10] root 505 0.0 0.0 0 0 ? S< 2010 0:00 [aio/11] root 506 0.0 0.0 0 0 ? S< 2010 0:00 [aio/12] root 507 0.0 0.0 0 0 ? S< 2010 0:00 [aio/13] root 508 0.0 0.0 0 0 ? S< 2010 0:00 [aio/14] root 509 0.0 0.0 0 0 ? S< 2010 0:00 [aio/15] root 665 0.0 0.0 0 0 ? S< 2010 0:00 [kpsmoused] root 808 0.0 0.0 0 0 ? S< 2010 0:00 [ata/0] root 809 0.0 0.0 0 0 ? S< 2010 0:00 [ata/1] root 810 0.0 0.0 0 0 ? S< 2010 0:00 [ata/2] root 811 0.0 0.0 0 0 ? S< 2010 0:00 [ata/3] root 812 0.0 0.0 0 0 ? S< 2010 0:00 [ata/4] root 813 0.0 0.0 0 0 ? S< 2010 0:00 [ata/5] root 814 0.0 0.0 0 0 ? S< 2010 0:00 [ata/6] root 815 0.0 0.0 0 0 ? S< 2010 0:00 [ata/7] root 816 0.0 0.0 0 0 ? S< 2010 0:00 [ata/8] root 817 0.0 0.0 0 0 ? S< 2010 0:00 [ata/9] root 818 0.0 0.0 0 0 ? S< 2010 0:00 [ata/10] root 819 0.0 0.0 0 0 ? S< 2010 0:00 [ata/11] root 820 0.0 0.0 0 0 ? S< 2010 0:00 [ata/12] root 821 0.0 0.0 0 0 ? S< 2010 0:00 [ata/13] root 822 0.0 0.0 0 0 ? S< 2010 0:00 [ata/14] root 823 0.0 0.0 0 0 ? S< 2010 0:00 [ata/15] root 824 0.0 0.0 0 0 ? S< 2010 0:00 [ata_aux] root 842 0.0 0.0 0 0 ? S< 2010 0:00 [scsi_eh_0] root 843 0.0 0.0 0 0 ? S< 2010 0:00 [scsi_eh_1] root 844 0.0 0.0 0 0 ? S< 2010 0:00 [scsi_eh_2] root 845 0.0 0.0 0 0 ? S< 2010 0:00 [scsi_eh_3] root 846 0.0 0.0 0 0 ? S< 2010 0:00 [scsi_eh_4] root 847 0.0 0.0 0 0 ? S< 2010 0:00 [scsi_eh_5] root 882 0.0 0.0 0 0 ? S< 2010 0:00 [kstriped] root 951 0.0 0.0 0 0 ? S< 2010 4:24 [kjournald] root 976 0.0 0.0 0 0 ? S< 2010 0:00 [kauditd] postfix 990 0.0 0.0 54208 2284 ? S 21:19 0:00 pickup -l -t fifo -u root 1013 0.0 0.0 12676 8 ? S<s 2010 0:00 /sbin/udevd -d root 1326 0.0 0.0 90900 3400 ? Ss 14:53 0:00 sshd: root@notty root 1410 0.0 0.0 53972 2108 ? Ss 14:53 0:00 /usr/libexec/openssh/sftp-server root 2690 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/0] root 2691 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/1] root 2692 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/2] root 2693 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/3] root 2694 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/4] root 2695 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/5] root 2696 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/6] root 2697 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/7] root 2698 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/8] root 2699 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/9] root 2700 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/10] root 2701 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/11] root 2702 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/12] root 2703 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/13] root 2704 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/14] root 2705 0.0 0.0 0 0 ? S< 2010 0:00 [kmpathd/15] root 2706 0.0 0.0 0 0 ? S< 2010 0:00 [kmpath_handlerd] root 2755 0.0 0.0 0 0 ? S< 2010 4:35 [kjournald] root 2757 0.0 0.0 0 0 ? S< 2010 3:38 [kjournald] root 2759 0.0 0.0 0 0 ? S< 2010 4:10 [kjournald] root 2761 0.0 0.0 0 0 ? S< 2010 4:26 [kjournald] root 2763 0.0 0.0 0 0 ? S< 2010 3:15 [kjournald] root 2765 0.0 0.0 0 0 ? S< 2010 3:04 [kjournald] root 2767 0.0 0.0 0 0 ? S< 2010 3:02 [kjournald] root 2769 0.0 0.0 0 0 ? S< 2010 2:58 [kjournald] root 2771 0.0 0.0 0 0 ? S< 2010 0:00 [kjournald] root 3340 0.0 0.0 5908 356 ? Ss 2010 2:48 syslogd -m 0 root 3343 0.0 0.0 3804 212 ? Ss 2010 0:03 klogd -x root 3430 0.0 0.0 0 0 ? S< 2010 0:50 [kondemand/0] root 3431 0.0 0.0 0 0 ? S< 2010 0:54 [kondemand/1] root 3432 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/2] root 3433 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/3] root 3434 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/4] root 3435 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/5] root 3436 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/6] root 3437 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/7] root 3438 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/8] root 3439 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/9] root 3440 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/10] root 3441 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/11] root 3442 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/12] root 3443 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/13] root 3444 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/14] root 3445 0.0 0.0 0 0 ? S< 2010 0:00 [kondemand/15] root 3461 0.0 0.0 10760 284 ? Ss 2010 3:44 irqbalance rpc 3481 0.0 0.0 8052 4 ? Ss 2010 0:00 portmap root 3526 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/0] root 3527 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/1] root 3528 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/2] root 3529 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/3] root 3530 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/4] root 3531 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/5] root 3532 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/6] root 3533 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/7] root 3534 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/8] root 3535 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/9] root 3536 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/10] root 3537 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/11] root 3538 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/12] root 3539 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/13] root 3540 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/14] root 3541 0.0 0.0 0 0 ? S< 2010 0:00 [rpciod/15] root 3563 0.0 0.0 10160 8 ? Ss 2010 0:00 rpc.statd root 3595 0.0 0.0 55180 4 ? Ss 2010 0:00 rpc.idmapd dbus 3618 0.0 0.0 21256 28 ? Ss 2010 0:00 dbus-daemon --system root 3649 0.2 0.4 563084 18796 ? S<sl 2010 179:03 mfsmount /mnt/mfs -o rw,mfsmaster=web1.ovs.local root 3702 0.0 0.0 3800 8 ? Ss 2010 0:00 /usr/sbin/acpid 68 3715 0.0 0.0 31312 816 ? Ss 2010 3:14 hald root 3716 0.0 0.0 21692 28 ? S 2010 0:00 hald-runner 68 3726 0.0 0.0 12324 8 ? S 2010 0:00 hald-addon-acpi: listening on acpid socket /var/run/acpid.socket 68 3730 0.0 0.0 12324 8 ? S 2010 0:00 hald-addon-keyboard: listening on /dev/input/event0 root 3773 0.0 0.0 62608 332 ? Ss 2010 0:00 /usr/sbin/sshd ganglia 3786 0.0 0.0 24704 988 ? Ss 2010 14:26 /usr/sbin/gmond root 3843 0.0 0.0 54144 300 ? Ss 2010 1:49 /usr/libexec/postfix/master postfix 3855 0.0 0.0 54860 1060 ? S 2010 0:22 qmgr -l -t fifo -u root 3877 0.0 0.0 74828 708 ? Ss 2010 1:15 crond root 3891 1.4 1.9 326960 77704 ? S<l 2010 896:59 mfschunkserver root 4122 0.0 0.0 18732 176 ? Ss 2010 0:10 /usr/sbin/atd root 4193 0.0 0.8 129180 35984 ? Ssl 2010 11:04 /usr/bin/ruby /usr/sbin/puppetd root 4223 0.0 0.0 18416 172 ? S 2010 0:10 /usr/sbin/smartd -q never root 4227 0.0 0.0 3792 8 tty1 Ss+ 2010 0:00 /sbin/mingetty tty1 root 4230 0.0 0.0 3792 8 tty2 Ss+ 2010 0:00 /sbin/mingetty tty2 root 4231 0.0 0.0 3792 8 tty3 Ss+ 2010 0:00 /sbin/mingetty tty3 root 4233 0.0 0.0 3792 8 tty4 Ss+ 2010 0:00 /sbin/mingetty tty4 root 4234 0.0 0.0 3792 8 tty5 Ss+ 2010 0:00 /sbin/mingetty tty5 root 4236 0.0 0.0 3792 8 tty6 Ss+ 2010 0:00 /sbin/mingetty tty6 root 5596 0.0 0.0 19368 20 ? Ss 2010 0:00 DarwinStreamingServer qtss 5597 0.8 0.9 166572 37408 ? Sl 2010 523:02 DarwinStreamingServer root 8714 0.0 0.0 0 0 ? S Jan31 0:33 [pdflush] root 9914 0.0 0.0 65612 968 pts/1 R+ 21:49 0:00 ps aux root 10765 0.0 0.0 76792 1080 ? Ss Jan24 0:58 SCREEN root 10766 0.0 0.0 66212 872 pts/3 Ss Jan24 0:00 /bin/bash root 11833 0.0 0.0 63852 1060 pts/3 S+ 17:17 0:00 /bin/sh ./launch.sh root 11834 437 42.9 4126884 1733348 pts/3 Sl+ 17:17 1190:50 /usr/bin/java -Xms128m -Xmx512m -XX:+UseConcMarkSweepGC -jar /JavaCore/JavaCore.jar root 13127 4.7 1.1 110564 46876 ? Ssl 17:18 12:55 /JavaCore/fetcher.bin root 19392 0.0 0.0 90108 3336 ? Rs 20:35 0:00 sshd: root@pts/1 root 19401 0.0 0.0 66216 1640 pts/1 Ss 20:35 0:00 -bash root 20567 0.0 0.0 90108 412 ? Ss Jan16 1:58 sshd: root@pts/0 root 20569 0.0 0.0 66084 912 pts/0 Ss Jan16 0:00 -bash root 21053 0.0 0.0 63856 28 ? S Jan30 0:00 /bin/sh /usr/bin/WowzaMediaServerd /usr/local/WowzaMediaServer/bin/setenv.sh /var/run/WowzaM root 21054 2.9 10.3 2252652 418468 ? Sl Jan30 314:25 java -Xmx1200M -server -Djava.net.preferIPv4Stack=true -Dcom.sun.management.jmxremote=true - root 21915 0.0 0.0 0 0 ? S Feb01 0:00 [pdflush] root 29996 0.0 0.0 76524 1004 pts/0 S+ 14:41 0:00 screen -x Any idea what could this be, or where I should look for more diagnostic information? Thanks.

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• A good interpreted language for a small embedded project

  - by Earlz

  I have an mbed which has a small ARM Cortex M3 on it. Basically, my effective resources for the project are ~25Kb of RAM and ~400Kb of Flash. For I/O I'll have a PS/2 keyboard, a VGA framebuffer(with character output), and an SD card for saving/loading programs(up to a couple of Mb maybe) The reason I ask this here is because I'm trying to figure out what programming language to implement on the thing. I'm looking for an interpreted language that's easy for me to implement, and won't break the bank on my resources. I also intend for this to be at least possible to write on th device itself, though the editor can be interpreted(yay bootstrapping) Anyway, I've looked at a few simple languages. Some nice candidates: Forth BASIC Scheme? Has anyone done something like this or know of any languages that can fit this bill or have comments about my three candidates so far?

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• What Are Some Advantages/Disadvantages of Using C over Assembly?

  - by Daniel

  I'm currently studying engineering in Telecommunications and Electronics and we have migrated from assembler to C in microprocessor programming. I have doubts that this is a good idea. What are some advantages and disadvantages of C compared to assembly? The advantages/disadvantages I see are: Advantages: I can tell that C syntax is a lot easier to learn than Assembler syntax. C is easier to use for making more complex programs. Learning C is somehow more productive than learning assembler cause there is more developing stuff around C than Assembler. Disadvantages: Assembler is a lower level programming language than C,so this makes it a good for programming directly to hardware. Is a lot more flexible alluding you to work with memory,interrupts,micro-registers,etc.

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• Were the first assemblers written in machine code?

  - by The111

  I am reading the book The Elements of Computing Systems: Building a Modern Computer from First Principles, which contains projects encompassing the build of a computer from boolean gates all the way to high level applications (in that order). The current project I'm working on is writing an assembler using a high level language of my choice, to translate from Hack assembly code to Hack machine code (Hack is the name of the hardware platform built in the previous chapters). Although the hardware has all been built in a simulator, I have tried to pretend that I am really constructing each level using only the tools available to me at that point in the real process. That said, it got me thinking. Using a high level language to write my assembler is certainly convenient, but for the very first assembler ever written (i.e. in history), wouldn't it need to be written in machine code, since that's all that existed at the time? And a correlated question... how about today? If a brand new CPU architecture comes out, with a brand new instruction set, and a brand new assembly syntax, how would the assembler be constructed? I'm assuming you could still use an existing high level language to generate binaries for the assembler program, since if you know the syntax of both the assembly and machine languages for your new platform, then the task of writing the assembler is really just a text analysis task and is not inherently related to that platform (i.e. needing to be written in that platform's machine language)... which is the very reason I am able to "cheat" while writing my Hack assembler in 2012, and use some preexisting high level language to help me out.

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• Why is learning assembly language seen as a disadvantage?

  - by cprogcr

  I was recently reading an article about making a compiler, and one of the disadvantages mentioned about making a compiler instead of interpreter, was "Learning Assembly language".I understand that perhaps it takes a little more time to learn ASM than it would take for a high level language. But why should it be seen as a disadvantage? And this is not the first time, I mean there are a lot of articles which see ASM as a disadvantage or not important.Personally I find ASM interesting and not at all as a "disadvantage".

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• How to start embedded development for developing a handheld game console?

  - by Quakeboy

  I work as a iPhone app developer now, so I know a bit of c, c++ and objective c. Also have fiddled with Java and many other. All of them have been just high level application/games development. My final goal is to make a handheld game console. More like a home made NES/SNES handheld console or even an Atari. I have found out about RaspberryPI and Arduino. But I need more information about how to approach this. 1) How Do I learn to pick the best board/cpu/controller/GPU/LCD screen/LCD controller etc? 2) Will learning to make a NES emulator first help me understand this field? If so are there any tutorials?

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• How to have an Arduino wait until it receives data over serial?

  - by SonicDH

  So I've wired up a little robot with a sound shield and some sensors. I'm trying to write a sketch that will let check the sensors. What I'd like for it to do is print out a little menu over serial, wait until the user sends a selection, jump to the function that matches their selection, then (once the function is done) jump back and print the menu again. Here's what I've written, but I'm not a that good of a coder, so it doesn't work. Where am I going wrong? #include <Servo.h> Servo steering; Servo throttle; int pos = 0; int val = 0; void setup(){   Serial.begin(9600);   throttle.write(90);   steering.write(90);   pinMode(A0, INPUT);   pinMode(7, INPUT);   char ch = 0; } void loop(){   Serial.println("Menu");   Serial.println("--------------------");   Serial.println("1. Motion Readout");   Serial.println("2. Distance Readout");   Serial.println("3. SD Directory Listing");   Serial.println("4. Sound Test");   Serial.println("5. Car Test");   Serial.println("--------------------");   Serial.println("Type the number and press enter");   while(char ch = 0){   ch = Serial.read();}   char ch;   switch(ch)   {     case '1':     motion();   }    ch = 0; } //menu over, lets get to work. void motion(){   Serial.println("Haha, it works!"); } I'm pretty sure a While loop is the right thing to do, but I'm probably implementing it wrong. Can anyone shed some light on this?

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• How to fix "The system is running in low-graphics mode" error?

  - by jokerdino

  Note: This is an attempt to create a canonical question that covers all instances of "low-graphics mode" error that occurs to a user, including but not limited to installation of wrong drivers, incorrect or invalid lightdm greeters, low disk space, incorrect installation of graphics card like ATI and Nvidia, incorrect configuration of xorg.conf file while setting up multiple monitors among others. If you are experiencing the "low-graphics mode" error when trying to login but none of the following answers work for you, please do ask a new question and then update the answers of this canonical question as and when your new question gets answered. When I try to boot into my computer, I am getting this error: The system is running in low-graphics mode Your screen, graphics cards, and input device settings could not be detected correctly. You will need to configure these yourself. How do I fix the failsafe X mode and login into my computer? Answer index: The greeter is invalid

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• What interface does python use to implement sockets?

  - by user2738698

  When I programmed in python, I believe I interfaced with the transport layer using sockets. If python was programmed by humans, they must have used an interface that was "lower" than sockets, to provide us with the interface to sockets. I assume firewalls, also programmed by humans, use interfaces of lower layers in the same manner, so is there a way to access such lower layers, in terms of programming?

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• Best Java 'framework' for LOW-END 3D Graphics?

  - by CodeJustin.com

  I've made my share of 2D games on various platforms but I have never developed a 3D game. I want to make a small "mmorpg". I already made my server in python and it works just fine with my flash 2D game but I decided I want to step it up and try out 3D. I want to make a 3D game for the web browser and I think Java might be a good choice for this. So basically I'm just looking for a straight forward and well documents 'framework' to make LOW-END 3D games. Keep in mind that I will be targeting peoples with very low-end PC's (plus my 3d modeling skills aren't great so I wouldn't mind hiding it somewhat, haha)

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• Question about mysql indexes on low to medium cardinality columns

  - by Kevin J

  I have a general question about the way that database indexing works, particularly in mysql. Let's say I have a table with a million rows with a column "ClientID" that is distributed relatively equally among 30 values. Thus, this column is very low cardinality (30) relative to the primary key (1 million). Now, I understand that you shouldn't create indexes on low cardinality fields. However, in this case, queries are only ever done with one of the 30 clientIDs. Thus, wouldn't creating an index on ClientID be helpful, as the search space is automatically reduced to 1/30th what it normally would be? Or is my understanding of how the index works flawed? Thanks

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• Need help with Drupal bulk mail low open rate for legitimate mailing list

  - by Ron Williams

  I've moved from constant contact to Drupal Simplenews/Mimemail/SMTP. Previously the open rate was around 50% for constant contact, but now it's 4-5% for the same list via the mentioned setup. Mail is getting out from the server, but it's having an issue anyway. Here's the setup: -The e-mail list consists of approximately 80,000 addresses which is queued at 10,000 e-mails per cron run (which runs hourly). -The server is a Dual Core2Quad machine with 2GB of RAM. -When mail is being sent, the mail queue will usually go up to ~1000 at the beginning of the hour before reducing to ~250 by the time the next cron occurs. -Newsletter is themed to display custom style for newsletter on send -Newsletter is received by some, but appears to be bounced by many (based on low open rate_ -I've added SPF, domain keys, and a PTR record to the DNS -Server hostname (listed in ptr) is different from hosted domain -Very low spam number via Spamassassin -IP and domain are not blacklisted -Mail goes out via SMTP module on delivery. Any ideas?

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• Rails - Preventing users from contributing to website when there score is too low - callback / obser

  - by adam

  A User can add a Sentence directly on my website, via twitter or email. To add a sentence they must have a minimum score. If they don't have the minimum score they cant post the sentence and a warning message is either flashed on the website, sent back to them via twitter or email. So I'm wondering how best to code this check. Im thinking a sentence observer. So far my thoughts are in before_create score_sufficient() - score ok = save - score too low = do not save In the case of too low i need to return some flag so that the calling code can then fire off teh relevant warning. What type of flag should I return? False is too ambiguous as that could refer to validation. I could raise an exception but that doesn't sound right or I could return a symbol? Is this even the right approach? What's the best way to code this?

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• Low memory with 640Kb of live bytes?

  - by Chiodo

  Hello, i've a problem with my application that need to display a lot of images and video. After running ObjectAlloc tool, i see that the live bytes is 640Kb and the overall memory is 31,54Mb when the application crash. In the organizer i get a "low memory" report so i guess the app crashed because low memory but the ObjectAllocation data don't make any sense to me... Any ideas? This is the Organizer crash log: Incident Identifier: CDCAF38C-CFFD-4316-9C4A-5C8E37794B49 CrashReporter Key: 65390aeb97b2b81076576c3e33b025feb5db9202 OS Version: iPhone OS 3.1.3 (7E18) Date: 2010-05-19 10:07:19 +0200 Free pages: 372 Wired pages: 12260 Purgeable pages: 0 Largest process: DTMobileIS Processes Name UUID Count resident pages ATreeTest <1d51c3a5fef8b747c3a1be9405bdd52a 1150 (jettisoned) (active) DTMobileIS <69c3fa96db2f29474d62964aa1a69bfa 3316 notification_pro <8a7725017106a28b545fd13ed58bf98c 68 mediaserverd <3d3800d6acfff050e4d0ed91cbe2467e 464 (jettisoned) syslogd <8eddddc00294d5615afded36ee3f1b62 56 (jettisoned) apsd <32070d91b216d806973c8f1b1d8077a4 173 SpringBoard <324939a437d1cca1fa4af72d9f5d0eba 2475 (jettisoned) (active) accessoryd <8f21c8b376d16e2ccb95ed6d21d8317a 99 (jettisoned) notification_pro <8a7725017106a28b545fd13ed58bf98c 64 ptpd 129 notifyd <591dd4dd804b4b8741f52335ea1fa4ab 64 CommCenter 167 configd <85efd41aceac34ccc0019df76623c7a9 294 fairplayd 91 mDNSResponder 101 lockdownd <80d2bd44c0bcca273d48ce52010f7e65 285 launchd 71 End

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• How to implement low pass filter using java

  - by chai

  Hello Everyone, I am trying to implement a low pass filter in Java. My requirement is very simple,I have to eliminate signals beyond a particular frequency (Single dimension). Looks like Butterworth filter would suit my need. Now the important thing is that CPU time should be as low as possible. There would be close to a million sample the filter would have to process and our users don't like waiting too long. Are there any readymade implementation of Butterworth filters which has optimal algorithms for filtering. Regards, Chaitannya

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• Running ubuntu in virtualbox, low screen resolution/dimensions

  - by sososo

  I am running windows 7 natively, i7 64 bit chipset. ATI radeon hd 4800 series video card. I have virtual box. For some reason, when running ubuntu in virtualbox, the screen rez is like 600x480 (very very small). Is this because ubuntu can't figure out my video card?

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• Apache jamming at low load average

  - by Apikot

  Apache seems to stop responding sometimes even though apache processes are still running. After restarting apache, the load average usually shoots up from 1 - 2 to 13 - 15 in a matter of seconds. What would the cause of this be, or how could I find out why apache stops serving? My httpd.conf is: <IfModule mpm_prefork_module> StartServers 8 MinSpareServers 5 MaxSpareServers 20 MaxClients 50 ServerLimit 50 MaxRequestsPerChild 4000 </IfModule> It's running on an EC2 c1.medium (1.7 GB of memory) Thanks

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• Win 7 running slowly with low CPU usage and memory

  - by guywhoneedsahand

  I have a relatively new (under 2 yrs old) windows 7 machine. It has 9GB of RAM, and an i7 core CPU (930 @ 2.8GHz w/ 8 CPUs). After about 8 months since a clean install, I noticed my computer was running slowly. I figure it was fragmentation etc, and I did a complete wipe & clean reinstall. However, my problems are somehow persisting. The computer is running painfully slowly (but in leaps and bounds - sometimes it will work fine for 3 hrs, then suddenly freeze up just from clicking the start button). The 'freezes' happen randomly - not during any especially intensive computing. I initially thought something might be eating through my CPU and/or Memory, but Task Manager indicates that neither the CPU or Memory spike. In fact, even during serious lag, CPU usage remains at less than 5% and Memory at ~ 1.5GB. It's beyond me why a fresh install on a powerful machine is performing so poorly... and it certainly is frustrating! What could be causing the poor performance, and what can I do to fix it?

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• High load average, low CPU and IO (Centos 5.7)

  - by Ben

  A Drupal 7 site with CiviCRM, after running smoothly for a year on a 1&1 VPS suddenly became unresponsive. Now pages eventually load, but can take more than a minute. Looking at resource use in Virtuozzo, the load average carries a warning, and has remained above 1. While I understand this isn't particularly high, this is a change from when the site was working. Here is a typical snapshot of top: top - 03:10:32 up 3:21, 1 user, load average: 1.16, 1.22, 1.30 Tasks: 43 total, 1 running, 42 sleeping, 0 stopped, 0 zombie Cpu(s): 0.1%us, 0.1%sy, 0.1%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 2097152k total, 1015112k used, 1082040k free, 0k buffers Swap: 0k total, 0k used, 0k free, 0k cached CPU idle level never seems to go much below 70%. wa is virtually always at 0. There appears to be lots of free memory. And here is some vmstat output, again showign wa at 0, plenty of free memory, and an idle CPU: procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------ r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 0 1100872 0 0 0 0 2783 23672 0 538 1 0 99 0 0 1 0 0 1100872 0 0 0 0 0 16 0 101754 0 0 100 0 0 0 0 0 1100872 0 0 0 0 0 17 0 103133 0 0 100 0 0 0 0 0 1100872 0 0 0 0 0 1 0 102080 0 0 100 0 0 1 0 0 1100872 0 0 0 0 0 6 0 99881 0 0 100 0 0 0 0 0 1100872 0 0 0 0 0 1 0 105187 0 0 100 0 0 I've spoken to 1&1 but they don't have any ideas as to what could be causing the high load average. Instead they suggested an upgrade :) I've looked for processes that might be causing this, examined MySQL showprocesslist, and restarted the container with no result. Does anyone have more troubleshooting suggestions or insights?

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• Low framerate on background apps

  - by user1698923

  My problem is that when a game is running in the foreground, in Full Screen mode, any applications on my second monitor (such as youtube videos, videos, not app specific) drop their frame-rate to about 2-3 FPS. It seems like some sort of power management option that I can't track down. As far as I can tell, it's not due to the GPU not being able to keep up. For instance, my PC can play League of Legends at about 280FPS when the framerate is uncapped. If i cap it at 60FPS using the in-game option, it has no affect on the performance of the background app. Summary Operating System Windows 8 Pro 64-bit CPU Intel Core i7 3820 @ 3.60GHz 42 °C Sandy Bridge-E 32nm Technology RAM 12.0GB Triple-Channel DDR3 @ 533MHz (7-7-7-20) Motherboard Gigabyte Technology Co., Ltd. X79-UD3 (SOCKET 0) 37 °C Graphics DELL U2713HM (2560x1440@59Hz) DELL U2713HM (2560x1440@59Hz) 1280MB NVIDIA GeForce GTX 570 (Gigabyte) 58 °C Hard Drives 212GB Volume0 (RAID) 1863GB Western Digital WDC WD20EARS-00MVWB0 (SATA) 36 °C 1863GB Western Digital WDC WD20EARS-00MVWB0 (SATA) 34 °C Optical Drives No optical disk drives detected Audio ASUS Xonar Essence STX Audio Device Operating System Windows 8 Pro 64-bit Computer type: Desktop Graphics Monitor 1 Name DELL U2713HM on NVIDIA GeForce GTX 570 Current Resolution 2560x1440 pixels Work Resolution 2560x1400 pixels State Enabled, Output devices support Multiple displays Extended, Secondary, Enabled Monitor Width 2560 Monitor Height 1440 Monitor BPP 32 bits per pixel Monitor Frequency 59 Hz Device \\.\DISPLAY4\Monitor0 Monitor 2 Name DELL U2713HM on NVIDIA GeForce GTX 570 Current Resolution 2560x1440 pixels Work Resolution 2560x1400 pixels State Enabled, Output devices support Multiple displays Extended, Primary, Enabled Monitor Width 2560 Monitor Height 1440 Monitor BPP 32 bits per pixel Monitor Frequency 59 Hz Device \\.\DISPLAY5\Monitor0 NVIDIA GeForce GTX 570 Manufacturer NVIDIA Model GeForce GTX 570 GPU GF110 Device ID 10DE-1086 Revision A2 Subvendor Gigabyte (1458) Series GeForce GTX 500 Current Performance Level Level 3 Current GPU Clock 845 MHz Current Memory Clock 1900 MHz Current Shader Clock 1690 MHz Voltage 0.988 V Technology 40 nm Die Size 520 mm² Release Date Dec 07, 2010 DirectX Support 11.0 OpenGL Support 5.0 Bus Interface PCI Express x16 Temperature 57 °C Driver version 9.18.13.2018 BIOS Version 70.10.55.00.01 ROPs 40 Shaders 512 unified Memory Type GDDR5 Memory 1280 MB Bus Width 64x5 (320 bit) Filtering Modes 16x Anisotropic Noise Level Moderate Max Power Draw 219 Watts Count of performance levels : 3 Level 1 - "Default" GPU Clock 50 MHz Memory Clock 135 MHz Shader Clock 101 MHz Level 2 - "2D Desktop" GPU Clock 405 MHz Memory Clock 324 MHz Shader Clock 810 MHz Level 3 - "3D Applications" GPU Clock 845 MHz Memory Clock 1900 MHz Shader Clock 1690 MHz Things I've tried: 1) Updating the graphics driver 2) Setting windows power mode to High Performance 3) Reset Nvidia Global Performance settings to default

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